This invention relates to a mechanical braking apparatus for use in retarding moving bodies.
Generally brakes, whether powered mechanically, electromagnetically, or by electromagnetic hydraulic devices, all require rather complicated, energy-consumable power producers. For instance, presently, brakes that are normally closed demand an additional power producer to deliver an external force to relieve them. Citing another example, the electromagnetic clutched brake has a normally closed state that uses spring force for braking and retarding a body. But when the body has to run or rotate, an electromagnet must be energized to produce electromagnetic force against the spring force to relieve the normally closed brake.
U.S. Pat. No. 2,783,861 discloses a drive-released brake, wherein the connecting mechanism is out of the transmission chain. More particularly, when the drive shaft 11 rotates the driven shaft 12 against a resisting load, the driven member 17 and the floating brake member 22 are each brought into a neutral or aligned position by the arm 16. Also, adjacent to the driven member 17 is a floating brake member 22 formed with a plurality of peripheral notches 23. The driven member 17 and the floating brake member 22 are each formed with three equal-spaced opposed radially extending V-shaped depressions, arranged so that they will be directly aligned. The brake and the release, as well as the power/torque transmission, are directly realized. Braking or relief of the braking, associated with the driving member 14 against the driven member 17, needs a driving power source. This structure evidently is rigidly connected, rather than elastically connected, wherein a ball retainer 29 and an antifriction ball bearing 28, and the above-mentioned V-shaped inclined ramps 26 and 27, only play a role in increasing power and do not take part in the power/torque transmission.
On Apr. 26, 1989, the Gazette of Patent for Chinese Invention disclosed a patent having application number 87102097, entitled xe2x80x9cBraking apparatus employing the brake force transformed from the inertial forcexe2x80x9d. In this patent, the braking apparatus comprises an additional power producer, a servo mechanism, brake mechanism, and reinforcement mechanism. The main external braking force is converted from the inertial force of the moving body, resulting in retarding the body. This apparatus has the features of short braking time, fast release, and working reliability. However, an additional power producer is still required to provide a brake operating force in its normal kinematics state, and a certain amount of energy must be consumed in the operation of the additional power producer.
In view of the previous facts, the invention is the further development of, and a major improvement over, current technology, including the aforesaid patent. The invention proposed is an apparatus having a compact structure, that achieves braking or the release of braking without additional power in its normal operation, or static, state.
Another object of the invention is to provide an apparatus that can apply braking or the release of braking by using the relative movement between the driving member and the driven member that emerges after the time that the driving member and driven member start and end their transmission.
A further object of the invention is to provide an apparatus that achieves braking or the release of braking by employing the concave-convex mating surface of the connecting mechanism between the driving member and the driven member.
First, in order to illustrate the content of the invention concisely, and for convenience, the implications of certain terminology in the invention description, xe2x80x9cdriving memberxe2x80x9d, xe2x80x9cdriven memberxe2x80x9d, xe2x80x9ca first direction movementxe2x80x9d, xe2x80x9ca second direction movementxe2x80x9d, etc., are shown as follows.
xe2x80x9cDriving memberxe2x80x9d and xe2x80x9cdriven memberxe2x80x9d: The driving member and driven member are not key structural elements of the brake invention, but they are the members used to connect the brake invention to the apparatus applying the brake invention. Regarding its relation to transmission, the driving member is located at the driving end, and the driven member is located at the driven end.
xe2x80x9cA first direction movementxe2x80x9d: This indicates the common movement carried out by the driving member when bringing the driven member into action, and also demonstrates the common movement made by the driving member and acting block. It also indicates the common movement carried out by the driven member and driving block. A first direction movement is called common movement for short.
xe2x80x9cA second direction relative displacementxe2x80x9d: This indicates the relative displacement made by the driving block or braking part relative to the friction surface on the fixed seat, or the relative displacement of the fitting or disengaging movement relative to the driven member or acting block, i.e., the relative movement or displacement when realizing braking or relieving braking. Therefore, a second direction relative displacement is also presented as the relative displacement of the fitting or disengaging movement.
The invention relates to a brake that comprises the connecting mechanism, enabling the driving member to bring the driven member into their common movement (i.e. movement taken along a first direction), a fixed seat having a friction surface, and a braking part which may engage or disengage the friction surface on the fixed seat, thereby achieving braking or the relief of braking for the driven member. According to the invention, the connecting mechanism is installed between the driving member and the driven member, and comprises a force switching mechanism. The force switching mechanism comprises an acting block, which may carry out a common movement (i.e. a first direction movement) with the driving member, and enables the braking part to produce relative displacement (i.e. a second direction relative displacement) by engaging or disengaging movement.
The acting block and driven block have a mating structure enabling relative movement when the driving member acquires active force or loses active force. The mating structure causes the driving block to have relative displacement (i.e. a second direction relative displacement) causing engaging or disengaging movement relative to the driven member, thereby realizing braking or relieving braking for the driven member.
The connecting mechanism also comprises a limiting mechanism in use for restricting the distance of relative motion between the acting block and driving block, when the braking or relief of braking is accomplished, the limiting mechanism ensuring that the driving member brings the driven member into their common movement (i.e. a first direction movement).
Also, in the brake, the movement taken along a first direction may be rotation.
Also, in the brake, the limiting mechanism can comprise a spring holding down the acting block, to ensure that after relative movement of the acting block and the driving block, they have adequate coactive force to carry out joint movement.
Also, in the brake, the limiting mechanism can comprise: A disc part connected to the driving member, wherein the disc part is installed with many pin shafts outside its center; and a disc part on the driven member, corresponding to the position of the pin shaft, wherein many long holes are installed along a circular arc direction on the disc part of the driven member, the pin shaft being movable relative to the long hole herein and finally suppressed to contact a certain end of the long hole.
Also, in the brake, the driving member and driven member may be installed up and down, the limiting mechanism comprising a disc part connected with the driving member, wherein many pin shafts are installed outside the center of the disc part, and a disc part connected with the driven member, corresponding to the position of the pin shaft, wherein many long holes are arranged in the circular arc direction on the disc part connected to the driven part, and wherein the pin shaft may finally contact a certain end of the long hole.
Also, in the brake, the mating structure that makes a relative movement between the acting surfaces of the acting block and driving block is a cam mating structure, and either the acting surface of the acting block or the acting surface of the driving block may be a cam surface, or both the acting surfaces of the acting block and the driving block are cam surfaces. When there is relative rotation between them, the driving block is able to produce a displacement (i.e. displacement relative to an engaging or disengaging movement) along a second direction relative to the acting block, thereby realizing braking or relieving braking.
Also, the brake can comprise a driving block movable relative to (i.e. second direction relative displacement) the axial direction of the rotating driven member, viz, a second direction relative displacement made by the driving block may be arranged in the axial direction of the rotating driven member.
Also, the brake can comprise a driving block movable relative to (i.e. second direction relative displacement) the radial direction of the rotating driven member, viz, a second direction relative displacement made by the driving block may be arranged in the radial direction of the rotating driven member.
Also, in the brake, the braking part and a disc part linked with the driven member become an integral structure by joining the compensation system and sliding key. The braking part is a disc having an inner gear ring. The disc part and the core enable the compensation system and sliding key to be set up. The compensation system is located between the disc and core. The sliding key causes common movement of the disc and core (i.e. first direction movement). The compensation system comprises the notch located at the edge of the core, a tooth block having teeth in the notch and matching with the disc, and a spring located between the tooth block and the bottom of the notch.
Also, in the brake, the two end faces of the acting block may be a structure mating with two driving blocks, respectively. Thus, the two end faces of the acting block taken along the axial direction of the rotating driven member may be concave and convex, such that the two end faces simultaneously mate with the two driving blocks.
Also, in the brake, the friction surface on the fixed seat may be a conical surface, flat surface, or cylindrical surface.
Also, in the brake, the first direction movement (i.e. common movement) can also be rectilinear movement, the brake comprising a driving block making a second direction relative displacement (i.e., displacement relative to an engaging or disengaging movement) along the vertical direction of the driven block that is making rectilinear movement, viz, a second direction relative displacement may be along the vertical direction of the driven member that is making rectilinear movement.
The previous description of conception and other objects and advantages will be further clarified by reference to the attached drawings illustrating the embodiment.